/*
 * Copyright 2015-2021 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.rsocket.loadbalance;

import io.rsocket.RSocket;
import java.util.List;

/**
 * Strategy to select an {@link RSocket} given a list of instances for load-balancing purposes. A
 * simple implementation might go in round-robin fashion while a more sophisticated strategy might
 * check availability, track usage stats, and so on.
 *
 * @since 1.1
 */
@FunctionalInterface
public interface LoadbalanceStrategy {

  /**
   * Select an {@link RSocket} from the given non-empty list.
   *
   * @param sockets the list to choose from
   * @return the selected instance
   */
  RSocket select(List<RSocket> sockets);
}
